Rotating seal for anti-stiction of hydraulic struts

Abstract

An onboard system for use in measuring, computing and displaying the weight and center-of-gravity for aircraft, while keeping aircraft movement to a minimum. Pressure sensors are mounted in relation to each of the landing gear struts. A motor and rotating seal are configured into each strut and are activated by a computer/controller, while landing gear strut pressures are monitored in the determination of strut stiction. The computer/controller calculates the stiction of each landing gear strut and compensates for the pressure distortions caused by landing gear strut stiction. Additional features include reducing strut stiction, measuring landing gear strut fluid levels, monitoring landing gear strut health, weight adjustments for external ice and de-icing fluids, weight adjustments for wind, monitoring aircraft landing gear strut movement.

1 . A strut for supporting an aircraft, comprising: 
 a cylinder defining a central axis;    a piston telescopically disposed within said cylinder;    a seal for maintaining a fluid-tight seal between said cylinder and piston; and    a mechanism for rotating said seal about said central axis.    
   
   
       2 . The strut of  claim 1 , wherein said seal comprises an O-ring.  
   
   
       3 . The strut of  claim 1 , wherein said mechanism for rotating said seal comprises a rotatable seal carrier disposed between said cylinder and said piston and configured to urge said seal against said piston.  
   
   
       4 . The strut of  claim 3 , wherein said mechanism for rotating said seal further comprises a motor for rotating said carrier.  
   
   
       5 . The strut of  claim 4 , wherein rotation is transferred from said motor to said seal carrier by friction.  
   
   
       6 . The strut of  claim 4 , wherein rotation is transferred from said motor to said seal carrier by gears.  
   
   
       7 . The strut of  claim 4 , wherein rotation is transferred from said motor to said seal carrier by a drive belt.  
   
   
       8 . The strut of  claim 3 , further comprising a second seal disposed between said seal carrier and said cylinder.  
   
   
       9 . The strut of  claim 8 , wherein said second seal comprises an O-ring.  
   
   
       10 . The strut of  claim 1 , further comprising a fluid contained within said cylinder that is subject to pressurization upon extension of said piston into said cylinder and a sensor for measuring pressure of said fluid.  
   
   
       11 . The strut of  claim 10 , wherein said fluid comprises a combination of hydraulic liquid and a compressible gas.  
   
   
       12 . The strut of  claim 10 , further comprising a computer for converting said measured pressure to a weight supported by said strut.  
   
   
       13 . A method of measuring weight supported by a strut, wherein a piston, defining a central axis, is telescopically received within a cylinder to pressurize a fluid therein and wherein a seal is disposed between said piston and cylinder, comprising: 
 rotating said seal about said central axis; and    measuring the pressure of said pressurized fluid.    
   
   
       14 . The method of  claim 13 , further comprising converting said measured pressure to a weight supported by said strut.  
   
   
       15 . The method of  claim 14 , wherein said fluid comprises hydraulic liquid and a compressible gas.  
   
   
       16 . The method of  claim 13 , wherein said seal is rotated by actuation of a motor.  
   
   
       17 . The method of  claim 16 , wherein said motor is affixed to said cylinder.  
   
   
       18 . The method of  claim 16 , wherein said seal is urged against said piston by a seal carrier that is rotationally engaged to said motor.  
   
   
       19 . The method of  claim 18 , wherein a second seal is disposed between said seal carrier and said cylinder.  
   
   
       20 . The method of  claim 19 , wherein said seals comprise O-rings.